Field of the Invention
The present invention relates to a tissue sampling device, and more particularly to a tissue sampling device for use in sampling body tissue.
Description of the Related Art
In recent years, a pathological definitive diagnosis has been made in such a manner that a puncture needle is introduced into a body cavity through a treatment tool insertion channel of an ultrasonic endoscope so that a cannula constituting the puncture needle is guided up to a region to be observed and is punctured into a diseased tissue to sample body tissue under ultrasonic tomographic image observation by the ultrasonic endoscope.
For example, there has been known a tissue sampling device for use in making such a pathological definitive diagnosis as disclosed in Japanese Patent Application Laid-Open No. 2005-73798 (hereinafter referred to as PTL 1). The tissue sampling device comprises a sheath flexible enough to be freely inserted into the treatment tool insertion channel of the endoscope; a cannula (puncture needle) inserted into the sheath so as to be movable back and forth and punctured into body tissue; and an operation unit connected to a proximal end portion of the sheath to move the cannula back and forth.